Keyless entry systems provide an alternative means of locking doors for those families with children ("latch key kids") who might often lose keys, people who are uncomfortable with hiding spare keys, owners of rental properties confronted with lock replacement costs attendant with tenant turnover and simply individuals who do not appreciate fumbling for keys while holding an armload of groceries. However, conversion from a keyed lock to a keyless system has been an expensive proposition since the installation has required professional expertise. Thus, there is a need for a system which can convert an existing keyed lock at minimal cost and time yet still provide the aforementioned advantages of keyless entry.